Project Summary Nonadherence to cardiac medications following an acute myocardial infarction (AMI) continues to be a problem despite efforts to increase adherence. Among patients following an AMI, nonadherence to cardiac medications can result in up to a 40% increase in re-hospitalization and an 80% increase in mortality. Developing effective interventions capable of targeting the multiple factors related to medication nonadherence, like mobile health applications (apps), is essential to improving health outcomes in adults following an AMI. Smartphone ownership continues to increase rendering them a potentially efficacious way of delivering health interventions. Thus far mobile apps have only been moderately successful in increasing medication adherence in this population. Attention needs to be paid to how patients engage with mobile technology so mobile health interventions can be effective in changing behavior and improving cardiovascular outcomes. The proposed dissertation study will be guided by a framework of user data analytics and the Conceptual Framework of User Engagement, both adapted by the applicant for mobile health, to evaluate user engagement with a mobile health app. The proposed study is nested within the Johns Hopkins Myocardial infarction, COmbined-device, Recovery Enhancement (MiCORE) parent study. Through the development of the heart attack recovery app, Corrie, the MiCORE study aims to improve medication adherence and decrease readmission rates in adults? post AMI at Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center. The purpose of this dissertation study is to evaluate the process of user engagement, individual predictors of user engagement and the relationship between user engagement and cardiac medication adherence in adults? post-AMI. Within a convenience sample of 200 adult patients enrolled in the MiCORE study, the specific aims of the dissertation study are to: 1. Examine the association between user engagement with Corrie and cardiac medication adherence, 2. Evaluate the interrelationships among the attributes of experienced user engagement to understand the process of user engagement with mHealth, and 3. Examine the relationships among user (sex, age, race, education) and mobile app experience (prior mobile app use, length of exposure to Corrie in hospital, perceived value of Corrie, ownership of vitals devices) characteristics and user engagement. In this predictive correlational design, user data analytics, the User Engagement Scale, and the 8-item Morisky Medication Adherence Scale will be used to evaluate user engagement with Corrie and cardiac medication adherence 30 days following hospital discharge. The proposed dissertation study and training plan directly align with the NINR?s mission to promote and improve health with a focus on wellness and the self-management of chronic conditions through innovative strategies. This study is important as it aims to identify intervention components salient for promoting user engagement, individual characteristics that affect user engagement, and the relationship between user engagement and cardiac medication adherence, to develop effective mobile health interventions for patients following an AMI.